1. Field of the Invention
In one aspect, this invention relates to carbonator systems.
In a further aspect, this invention relates to liquid level controls used in carbonated beverage systems and which require the admission of fresh makeup water to the system.
2. Description of the Prior Art
Present recirculating carbonator systems constantly draw carbonated water from a storage tank, cycle the water past a beverage dispensing head into a pump, and return the water to the storage tank in a closed loop. Such systems normally use two pumps. One pump is used to recirculate the carbonated water throughout the system, and the second pump is used to force makeup fresh water into the storage tank for carbonation. The use of two pumps adds additional expense and maintenance problems to the present recirculating system. In general, various electrical and mechanical systems have been combined with the dispensers to signal that the liquid in the storage tank has been depleted and to activate the second pump to force makeup water into the system. The electrical systems require expensive electrical circuitry and the mechanical systems are not as reliable as desired.
To overcome this problem, a one pump recirculating system was developed. This existing single pump recirculating system utilizes a double diaphragm valve which is spring biased to stay in an open position allowing recirculation during the normal circulating cycle. The valve is closed by means of a fluid amplifier when the liquid level in the storage tank falls below a predetermined level. This momentarily stops the carbonated water recirculation and the recirculating pump draws fresh water into the system through a check valve. The action of the double diaphragm valve is dependent upon the use of the fluid amplifier which channels the carbonated water recycled into the storage tank into a port which is in fluid communication with one side of the diaphragm.
This system depends on a signal generated by a stream of carbonated water directed into an open circuitous passage of the liquid level sensor to activate the diaphragm valve; the valve is then rather insensitive to changes in liquid level within the storage chamber. Also, the activating force can be affected by the line pressure of fresh water to be admitted to the system, such pressures having a wide variation on the order of 20 to 60 psi.